exhaust fit

[atrain40]

I have a 1991 kx500 that has a procircuit header and silencer. the problem is in CA many places need a SA, the silencer doesnt have that. so i was wanting to know if i could just replace the silencer with a stock one or any other kind and would it fit fine. thanks.

[Motorrad]

The stock silencer does not have a spark arrestor...

Any aftermarket silencer with a spark arrestor  I.E. FMF turbine core, Pro circuit has a few also  will fit right on what ever pipe it is you have..

The other option is to get a Sparky and weld, screw, rivit, etc  it on to your original pipe, also a good option

http://www.fmfracing.com/Mode/Category/65

http://www.procircuit.com/store/pc/viewCategories.asp?idCategory=265

[Johnniespeed]

 I use a  pro circut 296 spark arrestor, the decibles will pass the test and the spark arrestor passes the test.  It is a direct bolt on in place of the regular silencer.
 I have not tried any other brand of spark arrestor and hope others will comment on what they use.
 John

[Larry Wiechman]

I use a  pro circut 296 spark arrestor, the decibles will pass the test and the spark arrestor passes the test.

What is the decible limit and what did your bike score? 

[toomany]

I run a Pro Circuit Nature Friendly Spark Arrestor on my Kx5. Michigan has a 94db limit for sound. When I go to the sand dunes the ranger just waves me by without checking the sound. Only looks at the arrestor and sees it's a compliant one. My only complaint is my rear tire rubs on it, but I might be able to shim it out some.

[Larry Wiechman]

That 94db limit has me scared. I need to get a 500cc Honda thumper down to that level. I think the KX500's intake tract makes more noise than that limit.
 
Do they check on the trails, or just at Silver Lake?

[Johnniespeed]

In Michigan they only check quads and four strokes on the trails, but if you ask they will check your two stroke bike. The Bull Gap area and Silver Lake are the only places I am aware that check the noise levels.  They allow 96 decibels but 94 is the rule my silencer was three years old and still came in at 97, they simply suggest to repack and tell you to ride safe. I have been stopped in my truck at Silver Lake for a check but since they check at 2500 RPM, mine passes just fine. ( it would never pass at 4500 RPM )
 John

[Danger4u2]

I bought a "db Snorkel" and carry it with me just in case.  I've never installed it so I can't comment on how well it works or how well it stays on the bike.   http://www.thedbsnorkel.com/

[toomany]

That 94db limit has me scared. I need to get a 500cc Honda thumper down to that level. I think the KX500's intake tract makes more noise than that limit.
 
Do they check on the trails, or just at Silver Lake?

I have never been sound checked while out riding in the woods, only for a spark arrestor.

The only time you would get stopped and sound checked is if your bike is really loud. 4 strokes are louder and get checked more often. Silver lake will allow up to 98db, even though the official limit is 94. They just recomend repacking or adding an insert.